1. Field of the Invention
The present invention relates to inflatable curtains, and more specifically, to an apparatus and method for wrapping an undeployed inflatable curtain with a film.
2. Technical Background
Airbags and inflatable curtains are well accepted in their use in motor vehicles and have been credited with preventing numerous deaths and accidents. Some statistics estimate that frontal airbags reduce fatalities in head-on collisions by 25% among drivers using seat belts and by more than 30% among unbelted drivers. Statistics further suggest that with a combination of seat belts and airbags, serious chest injuries in frontal collisions can be reduced by 65% and serious head injuries by up to 75%. Thus, airbag and inflatable curtains use presents clear benefits.
In view of the apparent success of airbags and inflatable curtains, automobile designers and the consuming public have been anxious to increase the number of airbags and inflatable curtains present throughout a vehicle. Currently most automobiles being manufactured have driver and passenger side airbags. However, designers are identifying more and more locations to place airbags throughout the vehicle. For example, side impact airbags and overhead inflatable curtains are starting to appear in an increasing number of vehicles. These airbags and inflatable curtains prevent injury that might occur in a side-impact collision or other similar collision.
However, several design problems have been encountered in implementing multiple airbag and inflatable curtains throughout a vehicle cabin. For example, one such problem is the storage size of the inflatable curtain or airbag. Inflatable curtains such as those located along the roof rail may be large and bulky. A large storage size of some inflatable curtains may limit placement locations within a vehicle.
Furthermore, attempting to place an inflatable curtain in a small storage location increases the probability that the folded configuration of the inflatable curtain will be disturbed. Because the fold of an inflatable curtain typically determines the deployment sequence and characteristics of the inflatable curtain, changing the fold of the inflatable curtain may interfere with the inflatable curtain""s effectiveness. Disturbing the folded configuration may be even more probable with a large or awkwardly shaped inflatable curtain, where the shape and size make the inflatable curtain difficult to handle.
In order to minimize the storage size of inflatable curtains and to maintain a proper folded configuration, inflatable curtains have been wrapped in various wrapping materials. These wrapping materials maintain the folded configuration and storage size of an inflatable curtain until it deploys. Some materials used to wrap inflatable curtains and airbags may include nylon and plastic materials. These materials provide the proper balance between maintaining the folded configuration and allowing the inflatable curtain to deploy through the material at the desired instant.
The nylon material is typically implemented using a sock type configuration. The undeployed and folded inflatable curtain is enwrapped by the nylon sock by simply pulling the nylon sock around the inflatable curtain. The nylon sock maintains the storage size and folded configuration of the inflatable curtain. A similar configuration has also been accomplished through using a plastic material or thin film to enwrap the inflatable curtain. The plastic material or thin film may be provided in a tube shape that may be pulled around the undeployed and folded inflatable curtain.
Unfortunately, pulling an elongated and undeployed inflatable curtain through a nylon sock or thin film tube can be tedious and time consuming. Another drawback of using a sock or tube-like member is that many types of mounting members used to attach an inflatable curtain package to a vehicle are covered by the sock or tube. In ordered to release the mounting tabs from underneath the wrapping material, a number of slits or openings must be made in the material and mounting tabs must be manually pulled through the wrapping material.
This increased number of steps in the manufacturing process increases the cost and cycle time of manufacturing an inflatable curtain package. Additionally, manually cutting a series of slits or openings in the wrapping material presents the potential for damage to the wrapping material or inflatable curtain, causing the inflatable curtain to not deploy properly. Thus, current methods for maintaining the storage size and folded configuration of an inflatable curtain do not provide the most efficient and effective ways of wrapping a material around an inflatable curtain or airbag.
Therefore, what is needed is a method and apparatus that is capable of rapidly and inexpensively wrapping a confining material around an undeployed and folded inflatable curtain. Furthermore, a method for easily presenting mounting tabs out of the wrapping material is also needed.
The apparatus and method of the present invention have been developed in response to the present state-of-the-art, and, in particular, in response to problems and needs in the art that have not yet been fully resolved by currently available airbag and inflatable curtain systems. Thus, one objective of the present invention is to provide an apparatus and method to wrap inflatable curtain for installation. Another objective of the present invention is to provide an apparatus and method to maintain the folded configuration of inflatable curtain by shrink wrapping a film around the curtain. Other objectives of the present invention will become obvious from the following disclosure.
An inflatable curtain package is provided comprising an inflatable curtain and a thin film. The inflatable curtain has a deployed state and an undeployed state. The undeployed inflatable curtain may be in a rolled configuration or folded configuration. Furthermore, the undeployed inflatable curtain may be a generally oblong and elongated shape. In the undeployed state the inflatable curtain has a plurality of mounting tabs extending from the inflatable curtain.
The undeployed inflatable curtain is wrapped in a thin film. The thin film is characterized as having a first edge and a second edge, such that the thin film may substantially enwrap the inflatable curtain, while in deployed state. The wrapping of the thin film is configured to overlap the first edge and the second edge of the thin film. The thin film is comprised of material that is capable of releasing the inflatable curtain as the inflatable curtain deploys. The thin film may incorporate a perforation along its length to provide a separation point in the thin film from which the inflatable curtain made deploy.
Furthermore, the thin film may be a shrinkable material that shrink wraps around the undeployed inflatable curtain. The thin film could be shrink wrapped by placing the inflatable curtain package, comprising the undeployed inflatable curtain enwrapped by the thin film, in an oven for a duration of time. Additionally, the thin film may be made of a material that allows the first edge and the second edge of the thin film to be heat sealed together.
The method for creating the inflatable curtain package may be accomplished by first providing a thin film and an undeployed inflatable curtain. The thin film may have a first edge and a second edge and the undeployed inflatable curtain may have a plurality of mounting tabs attached at an attachment location.
The thin film enwraps the inflatable curtain by first selectively aligning the first edge of the thin film to a position proximate to the attachment location of the mounting tabs. Next the mounting tabs are positioned substantially over the first edge of the thin film. Then, the second edge of the thin film is selectively aligned to a position of overlapping the first edge and the attachment location. The alignment of the second edge should be such that the thin film substantially enwraps the undeployed inflatable curtain.
Once the thin film is wrapped around the inflatable curtain, the overlap may be sealed. Various methods may be employed to accomplish the sealing process. One method is to apply a heating element to the overlap, such that the two edges of the overlap bond together. Alternatively, an adhesive tape or chemical material may be used to seal the two edges together.
After the thin film is sealed around the inflatable curtain, the thin film may be shrink wrapped. Shrink wrapping may be accomplished by placing the inflatable curtain wrapped by the thin film in an oven for determined amount of time. Depending upon the properties of the thin film, the thin film will shrink around the inflatable curtain to maintain the folded configuration and, in some instances, decrease the folded size of the inflatable curtain.
The thin film may be supplied for manufacturing in several ways. The thin film may be provided in a pre-cut sheet that is sized for the individual inflatable curtains. Alternatively, the thin film made be continuously fed from a roll and cut to the desired length corresponding to the length of the undeployed inflatable curtain. Furthermore, a perforation may be added to the thin film before or after the thin film is wrapped around the undeployed inflatable curtain.
One specific embodiment of a method for manufacturing an inflatable curtain package may comprise first providing a thin film and an inflatable curtain, as discussed previously. The thin film may have a first edge and the second edge and the undeployed inflatable curtain may have a plurality of mounting tabs attached at an attachment location. The thin film may then be placed in a channel, such that the first edge and the second edge protrude from the channel. Then the undeployed inflatable curtain is placed in the channel on top of the thin film.
Next a first blade is tangentially displaced across the undeployed inflatable curtain. While displacing across the undeployed inflatable curtain the first blade displaces the first edge of the thin film over the undeployed inflatable curtain to a position proximate to the attachment location. Then, a second blade tangentially displaces across the undeployed inflatable curtain, such that the second blade further displaces the second edge of the thin film and the mounting tabs over the first blade. Finally, the first blade is retracted and the first edge and second edge of the thin film are adhered together.
These and other possible advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.